Persistence Cave and The Cool Phenomenon Called Cave Breathing

11 years ago, a worker at Wind Cave National Park in South Dakota found an untouched cave. The park service dubbed the find Persistence Cave but haven’t told the public about it until now.

Why the secrecy? The National Park Service wants to prevent the public from trying to explore the cave and damaging what lies inside. Excavation of the Persistence Cave is expected to begin today by members of a National Park Team and Jim Mead, a professor at East Tennessee State University.

Preliminary samples were gathered at the entrance of the cave and revealed three animal species that researchers didn’t know lived in the Black Hills area. The three discovered were the pika, platygonus and pine marten.

Besides hunting for bones, researchers will also collect sediment samples. The cave is an untouched source of information about the Black Hills climate dating back thousands of years. One important question researchers will aim to answer is how the area’s climate has changed over time.

The National Park Service believes the cave could be massive due to the direction and speed of the wind that blows out from its only known entrance.

“Something with this kind of potential and blowing this strong, we haven’t found anything like that before (in the park),” said Rod Horrocks, a Wind Cave national park scientist, to the AP.

It’s called ‘cave breathing’

Many caves are so large they have their own air pressure system. The direction of the wind differs depending on the barometric pressure on the surface. The air pressure system in large caves is always trying to maintain equal pressure with the surface.

If the barometric pressure is rising on the surface, air is forced inside the cave to normalize pressure. The exact opposite happens as the barometric pressure falls. Hence, cave breathing.

Researchers can get an estimate of how big the cave is by measuring the barometric airflow from the cave’s entrance.

Here’s a great video of cave breathing from the Wind Cave entrance in South Dakota.

The National Park Service is keeping the location of Persistence Cave under wraps until excavation and exploration are completed.

Mead told the AP he expects to find thousands of bones during the excavation. “I’d be surprised if we don’t have at least 100,000 bones by the time we’re done this summer.”